Donna/Serene: although 1388/1688 are the most popular aft cabins, I don't agree and here's why:
1) as I wrote, they are more expensive (D1 vs DA/DB)
2) they're known as "C cabins priced as Ds"... I disagree here since in a C cabin you don't only have more room, you have larger closets, an extra sofa, etc. in these cabins you just have an empty space, plus a pole. If you really need more room go for it but IMHO it is useless
3) they are the least private cabins in a way, since part of your balcony can be seen from Island Grill on deck 11!
Chrissy: If you want total privacy, yes, the side balconies are better. Actually in most aft cabins you can see your neighbor by putting your head out of the balcony, or by loooking down. But overall you won't be spied on unless people really want to spy on you.
Denise and Hi C: glad you liked my website
Hi C & serene: indeed 8390/8690 have a single door instead of sliding doors, but it really is an unsignificant detail (at least for me it was). Hi C don't worry about the light going in! And yes there is a side view through the hole but you can only see the sea (not the side of the ship). You will be staying in the same cabin I stayed in 8 months ago!